Aseismic faulting following the 1973 Nemuro-oki earthquake, Hokkaido, Japan (a retrospective study)
Aseismic faulting following the 1973 Nemuro-oki earthquake, Hokkaido, Japan (a retrospective study)
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1973 年日本北海道根室大地震后的抗震断层活动（回顾性研究）
DOI：
10.1007/bf00877774
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发表时间：
1980
影响因子：
2
通讯作者：
T. Kato
中科院分区：
文献类型：
--
作者：
K. Kasahara;T. Kato
本文分析了北海道东南部花崎的潮汐记录，以阐明1973年日本根室冲地震的震后地壳垂直运动。结果表明，Kasahara（1975）所推测的震后隆升在1975年末结束，并恢复到以前约1cm/yr的快速沉降速率。地震后隆起的停止，比以前推测的要早得多，可以用补充机制来解释，如断层表面对蠕动的摩擦阻力。然而，这种意想不到的运动方式提出了一个关于该地区构造运动累积的新问题。由于从过去几千年的地貌资料推算出的沉降速度比上述的近期沉降速度低了几乎一个数量级，我们必须对这两个速度之间的差异提供一些替代解释。换句话说，在这个地区，由于板块俯冲而引起的地震周期中的同震、震后和震间运动的简单重复必须得到修正。对俯冲过程提出了几种可能的修正，并对每种情况下的垂直运动进行了简要讨论。
Tidal records at Hanasaki, southeastern Hokkaido, are analysed to clarify the post-seismic crustal vertical movement in the 1973 Nemuro-oki, Japan, earthquake. The result shows that the post-seismic uplift, as speculated byKasahara(1975), terminated in late 1975 and reverted to the previous rate of rapid subsidence of about 1 cm/yr. Ceasing of the post-seismic uplift, which occurred much earlier than previously speculated, could be explained by supplementary mechanisms, such as frictional resistance against creeping at the fault surface. This unexpected mode of movement, however, raises a new question about the accumulation of tectonic movements in this district. Since the subsidence rate extrapolated from geomorphological data for the past several thousand years is almost one order of magnitude lower than the recent rate as mentioned above, we have to provide some alternative explanation for the discrepancy between the two rates. In other words, simple repetition of co-, post- and inter-seismic movements in seismic cycles due to plate subduction, must be modified in this district. Several possible modifications to the subduction process are suggested, and a brief discussion of vertical movements expected in each case is given.